Table of Contents
The CAP conjecture was firstly proposed by Eric Brewer and formally proved by Seth Gilbert and Nancy Lynch later. The theorem states the following three properties can not be guaranteed at the same time:
Consistency: The consistency guarantees the total order on all operations, which means the whole system looks like a single instance to the outside world, and all the read/writer operations are handled in an atomic consistent way.
Availability: Every non-failing node in the system must give a response when it receives a request and every request must terminate.
Partition Tolerance: A partitioned network means messages could be dropped when sent from one partition to another one in the network.